1. Field
The presently disclosed subject matter relates to laser light-emitting apparatuses, in which a laser beam emitted from a laser chip is wavelength-converted by a wavelength converting board, and more particularly relates to reliable laser light-emitting apparatuses having favorable optical characteristics and a high workability, which can be used for various lighting units such as a vehicle headlight and the like with a simple structure.
2. Description of the Related Art
Laser light-emitting apparatuses, in which a part of a laser beam emitted from a laser chip is converted into light having a different wavelength by a wavelength converting layer and in which a mixture light including the light having the different wavelength mixed with the laser beam emitted directly from the laser chip is emitted, have been used as a light source for various lighting units. In this case, laser light-emitting apparatuses, in which the laser chip may be located at a desired position by using an optical fiber, have also been known.
A first conventional laser light-emitting device, which may be used for such a laser light-emitting apparatus, is disclosed in Patent Document No. 1 (Japanese Patent Application Laid Open H08-228045). FIG. 9a is a schematic enlarged perspective view showing a first conventional laser light-emitting device, and FIG. 9b is a schematic enlarged cross-sectional view taken along Line A-A shown in FIG. 9a showing the first conventional laser light-emitting device, which is disclosed in Patent Document No. 1.
The first conventional laser light-emitting device 60 includes: a first sub mount 66 having a cavity located between a first top surface and a second top surface thereof; a first external electrode 64a formed on the first top surface of the first sub mount 66; a second external electrode 64b formed a bottom surface of the cavity of the first sub mount 66; a third external electrode 64c formed on the second top surface of the sub mount 66; a laser chip 67 mounted on the second external electrode 64b via a first solder 68; a heat sink 61 attaching the first sub mount 66 along with the laser chip 67 via a second solder 62; and a second sub mount 63 connecting to the first electrode 64a, the third external electrode 64c and the laser chip 67 via a third solder 65.
Accordingly, the conventional laser light-emitting device 60 may emit a laser beam emitted from the laser chip 67 toward the cavity of the first sub mount 66 so that the laser beam passes though the cavity. In this case, the conventional device 60 may radiate a heat directed toward the first sub mount 66 in heats generated from the laser chip 67 from the heat sink 61 via the second solder 62, and also may radiate a directed toward the second sub mount 63 in the heats from the second sub mount 63 via the third solder 65. However, when the conventional device 60 is used as a light source for a vehicle headlight and the like, which must be used under tough environments, because the laser chip 67 is not sealed by the first sub mount 66 and the second sub mount 63 and is exposed from the cavity, the conventional laser light-emitting device 60 may have concerns about a reliability under the tough environments.
A second conventional laser light-emitting device using a sealed laser chip, which may be used for a laser light-emitting apparatus including an optical fiber, is disclosed in Patent Document No. 2 (Japanese Patent Application Laid Open 2008-294259). FIG. 10a is a schematic enlarged cross-sectional front view showing a second conventional laser light-emitting device, and FIG. 10b is a schematic enlarged bottom view showing the second conventional laser light-emitting device, which is disclosed in Patent Document No. 2.
The second conventional laser light-emitting device 70 includes: a stem 74; a laser chip 73 mounted in a can-package, which is mounted on the stem 74; a lens holder 78 covering the can-package on the stem 74, and including an optical lens 76, which passes thought a laser beam emitted from the laser chip 73; a base board 71 having fixing openings 72 and a screw opening 77 attaching the stem 74 along with the laser chip 74 and the lens holder 78 using a fixing screw 79, which screws in the screw opening 77 to attach the stem 74 to the base board 71; a fiber holder 80a attached to the lens holder 78, and attaching a fiber sleeve 80b; an optical fiber module 82 attached into the fiver sleeve 80b; and a protecting cover 81 covering the fiber holder 80a and the fiver sleeve 80b, and holding the optical fiber module 82.
Hence, the second conventional laser light-emitting device 70 may emit a laser beam emitted from the laser chip 73 toward the optical fiber module 82 via the optical lens 76 so that the laser beam passes into an optical fiber in the optical fiber module 82. However, although the laser chip 73 may be sealed by the can-package, the conventional device 70 may not be necessarily radiate a heat generated from the laser chip 73 efficiently, because the laser chip 73 is mounted on a mounting surface in the sealed can-package. Additionally, neither the first conventional device 60 nor the second conventional device 70 include a wavelength converting material, and therefore may emit different color lights from each of the laser beams for the laser chips 67 and 73.
Therefore, Applicant of this disclosed subject matter discloses a reliable laser light-emitting apparatus using a can-typed laser chip, which may emit various color lights at a high radiating efficiency in Patent document No. 3 (U.S. Patent Publication No. 2015/0372200 A1), and also discloses a laser light-emitting apparatus using a sealed laser chip and an optical fiber, which may emit various color lights at a high reliability and which can be used as a light source for a headlight and the like in Patent document No. 4 (U.S. patent application Ser. No. 14/951,609). Additionally, Applicant of this disclosed subject matter discloses reliable laser light-emitting apparatuses having favorable optical characteristics, which can be used for a vehicle headlight and the like with a simple structure in Patent document No. 5 (U.S. patent application Ser. No. 14/937,823).
FIG. 11a is a schematic enlarged top view depicting a conventional laser light-emitting apparatus, and FIG. 11b is a schematic enlarged cross-sectional view taken along Line v-v shown in FIG. 11a depicting the conventional laser light-emitting apparatus, which may emit various color lights including a substantially white color light and which is disclosed in Patent document No. 5.
The conventional laser light-emitting apparatus 90 includes: a holder 93 including a supporter and a fixing frame attached on a base board of a package 92, which surrounds a laser chip LD having an incident surface LD-LS; a converting board holder BD attached into the fixing frame of the holder 93; each of leads 96 being electrically connected to a respective one of electrodes of the laser chip LD; and a wavelength converting board FC formed in a substantially planar shape, and incorporated into the converting board holder BD, wherein a laser optical axis OA of the laser chip LD passes though each of openings of the supporter and the fixing frame of the holder 93, and intersects with the wavelength converting board FC at a substantially right angle.
According to the above-described laser light-emitting apparatus 90, the wavelength converting board FC can receive a laser beam emitted from the incident surface Ld-LS of the laser chip LD, and also can convert a part of the laser beam into light having a different wavelength. Accordingly, the conventional laser light-emitting apparatuses 90 can emit various color lights including a substantially white color light having favorable optical characteristics, which can be used for a vehicle lamp, etc. However, the laser light-emitting apparatus 90 needs a process for connecting each of the leads 96 to the respective one of the electrodes of the laser chip LD, and therefore may not necessarily be an apparatus having a high workability.
The above-referenced Patent Documents are listed below, and are hereby incorporated with their English abstracts in their entireties.
1. Patent Document No. 1: Japanese Patent Application Laid Open H08-228045
2. Patent Document No. 2: Japanese Patent Application Laid Open 2008-294259
3. Patent Document No. 3: U.S. Patent Publication No. 2015/0372200 A1
4. Patent document No. 4: U.S. patent application Ser. No. 14/951,609
5. Patent document No. 5: U.S. patent application Ser. No. 14/937,823
The presently disclosed subject matter has been devised to consider the above and other problems, features, and characteristics in the conventional art devices. Embodiments of the disclosed subject matter can include reliable semiconductor light-emitting apparatuses that can emit mixture lights having favorable optical characteristics such as a high uniform color tone, a high light-emitting intensity and the like, which can be used for a vehicle lamp and the like, and which can also include an optical fiber. Accordingly, the semiconductor light-emitting apparatuses can emit the mixture lights including a substantially white color tone having a high light-emitting intensity from a small opening thereof, which can be used for lighting units such as a vehicle headlight that controls light emitted from the light-emitting apparatus using a reflector and/or a projector lens. The disclosed subject matter can also include providing reliable laser light-emitting apparatuses having a high workability due to a simple structure.